Idea for a little extra aero efficiency..

[marcush.]

A good reason for adding Ethylene Glycol to a cooling system is because it raises the boiling point of water. 30% of glycol raises the boiling point to 104.4 C. As mentioned in a earlier post the hotter the coolant the greater the radiator efficiency ,plus less chance your F1 car sits on the grid doing an impersonation of a Stanley Steamer.

right you raise the boiling point but you got less heat transfer ,so I´d say improved cooling beats boiling point ...we do have pressurised system to avoid boiling ..if this were a important factor-boiling point -then why not use pure glycol?
sure as hell every modern mass produced car has a bit more than 104°C in terms of maximum allowable water temp ,right?

At 2.7bar pure water is boiling at 130°C , at 4,75bar at 150°C...unfortunatelly the pressure in the system allowed is restricted already by regulation....

[Craigy]

For it to work you would need to hold a some coolent in the rear wing, which is high up and is still a weight in totaly the wrong place. There is no point where you would ever want to put weight high up in and f1 car unless you had too.

I like the concept really i do. But i cant see how the trade off would be worth it

So it's a compromise between (slightly) better aero versus a rise in CoG and polar moment of inertia.

I wonder how much more grip the car would have because of the smaller sidepods permitted by secondary cooling. Impossible to guess without loads more info than I have..

C

[Craigy]

sure as hell every modern mass produced car has a bit more than 104°C in terms of maximum allowable water temp ,right?

Pressure affects boiling point too. The higher the pressure, the higher the temperature before the water will boil. I'm not sure what the boiling point of water is at 3.75bar.

150C? 160C? 120C?

Does anyone have data?

C

ETA: I think it's about 141C

[marcush.]

sure as hell every modern mass produced car has a bit more than 104°C in terms of maximum allowable water temp ,right?

Pressure affects boiling point too. The higher the pressure, the higher the temperature before the water will boil. I'm not sure what the boiling point of water is at 3.75bar.

150C? 160C? 120C?

Does anyone have data?

C

ETA: I think it's about 141C

this is about right ...but how is the rule formulated -maximum pressure in the system allowed -absolute 3,75 bar OR 3.75 bar pressure-above normal???...that would give another 10°c ....

[BreezyRacer]

This is just so bad on so many levels ..

However here's a nugget that I wondered about for rear wings that's also out there but might have some potential.

Get rid of the airbox inlet and instead feed the motor with an air inlet on the upper surface of the rear wing. It would reduce drag in the body and the upper surface of the wing, allow better airflow to the wing, and provide one damn powerful ram air effect on the intake.

Of course the intake port logistics and aero are quite touchy but it has much more potential than mounting a radiator up there!

[riff_raff]

Craigy,

The location of the radiator duct inlets and outlets is controlled fairly tightly by F1 regulations. So is the coolant system pressure and coolant composition.

But here's a thought for you: There's no such limits on an air-cooled engine. With modern manufacturing techniques and aluminum alloys, it just might be possible to make an aircooled engine work in F1. A significant portion of the heat rejection in a modern F1 engine is already accomplished through the fuel latent heat effects in the intake system and through the lube oil flow. The benefits of an aircooled engine would be significantly less weight, better reliability, and a much more compact engine package.

Think about it. The transfer of heat directly from the engine structure into the passing airflow is much more efficient than heat transfer from the engine structure to a coolant circuit, to a heat exchanger core, and then to the passing airflow. It all boils down to the surface area, the specific heat of the interface flows, and the delta T between them. All of these variables favor a "high tech" aircooled design.

I would propose that a cylinder block and cylinder head machined from modern high-temp capable wrought aluminum alloys, with thin and very closely pitched cooling fins, and designed using using modern FEA and CFD codes for optimal heat transfer, could be made to work in an F1 engine.

What do you guys say?

Regards,
Terry

[marcush.]

literally a cool idea riffraff ...

[riff_raff]

very funny marcush.

But my proposal is serious. I think that an aircooled F1 engine could be up to 15% lighter than a liquid cooled one.

With modern F1 fuels, detonation is not too much of an issue. So cylinder head temps can be run quite high. A liquid cooled engine head must be cast, and cast aluminum alloys usually are limited to temperatures of about 250degF or less for strength reasons. Plus the water coolant temp is limited to about 230degF by regulations.

But a fully machined aircooled head made from high-strength wrought aluminum alloys (like 7075) could safely operate at temperatures of 400degF. This much higher deltaT between the heat exchange surface and the passing airflow means that much more heat energy can be rejected with a much smaller cooling mass airflow. Which also means much lower cooling drag losses.

Elimination of the radiators and coolant would eliminate about 20 or 30 pounds of weight. No radiators in sidepods would also mean a reduced polar MOI. And no radiators would mean no more DNF's due to coolant leaks.

I can even imagine a finned, aircooled cylinder head made from a diffusion bonded stack of CNC water jet cut 7075 aluminum sheet blanks. The fins would be only about 1mm thick, and separated by 1mm spacers, giving a fin density of 12.5 fins per inch. A cylinder head made like this would be super strong and very light. Plus it would have a very effective heat transfer rate.

Come on now guys, work with me here =D>

Terry

[Belatti]

Craigy, I have thought about a similar idea before but not located in the rear wing (mainly cause of the dowturns the guys here mentioned). Instead I have thought about water running through the body panels. Of course carbon fiber is not good tranfering heat and purging the system can be a issue.

About Terrys idea, well, it seems smart but I still have a doubt about air cooled engines.

Look: this little 125cc monster can pump 55HP. Thats 440HP per liter, in an F1 engine that would be 1056HP! (Ignore its a 2 strokes engine)



I have that same engine in my kart, a less compressed and single carb mouth version (because Im not a millionaire ) that can pump reliable 38HP. Here in Argetina those still are ahead of the water cooled ones because they are simpler, cheaper, lighter and dont have a water pump consuming power. Downturn is on hot summer days.

... A significant portion of the heat rejection in a modern F1 engine is already accomplished through the fuel latent heat effects in the intake system...

One of the first things you have to do when karting with the engine above is to "carburate" it: you have to play with air-fuel mixture (high and low RPM bolts in the carb) and that depends on to the weather and what you would like the engine to do.
A too rich mixture assures lubrication and maintains the engine very cool, although it will lack power.
A poor mixture will literally make the engine a fast rocket and blow up some seconds later. It just cant handle the heat.
Fuel mixture is very very important in a air cooled engine.

Some links:
http://www.aircooledtechnology.com/
http://www.enginehistory.org/air-cooled_cylinders_1.htm
http://www.bajajusa.com/air%20cooled%20 ... cooled.htm
http://en.wikipedia.org/wiki/Volkswagen ... led_engine

[marcush.]

I could not resist ,riffraff ...apologies there as I´m really intrigued by your
unearthing of aircooling the engine.
Honestly speaking ,if one looked up the finer details of core design in modern cars
I´m pretty sure you could improve surface area and flow character for an aircooled engine dramatically as well.
I assume you will also need something in terms of a fan to direct air where you need
it and when you need it as well ...as Porsche still did a few years ago...the last aircooled 911 was the 993 wich was build until 1998
The 935(group 5) and sportscars 936 and 956 models from ...i think it was 1978 used watercooled heads though ...

[Carlos]

Air cooling could certainly work. The Honda RA302 3L V8 produced 430HP using ducts and something called Vortex cooling.
http://www.f1technical.net/f1db/cars/232

The Porsche 917 4.5 flat 12 produced about 520HP.
"At 4.5-litres, the 917 was by far the largest air-cooled race engine ever built and, as such, it relied heavily on a large fan mounted atop the cylinders. At an engine speed of 8400 rpm, this gear-driven fan sucked a massive 2400-litres of cooling air with 65 percent devoted to the finned cylinders. It is also said that the oil lubrication system was more heavily relied upon to remove heat; a massive oil cooler (with the chassis tubes used to circulate the oil) was essential. In certain models, oil squirters also cooled the pistons."
http://autospeed.com/cms/title_The-Earl ... rticle.htm



Tatra built air cooled V8's for cars until 1998.

Tatra still builds an air cooled V12 turbo diesel that meets Euro5 emission standards.
http://www.tatra.cz/en/zajimavosti/Pres ... eEURO5.pdf (1 page)
One other note; engine oil play a large part in cooling an air cooled engine.

[marcush.]

power per litre ,yes but don´t forget the big aviation engines like pratt&whitney wasp etc with power figures of 1000+hp for their 9zylinder star engines followed up by twin row star engines...all aircooled....

[xpensive]

There was also this magificient Flat-16 prototype built by Porsche, never raced though, but hey, 840 Hp from 6.7 liters.

http://www.supercars.net/cars/2858.html

[Belatti]

Reading Carlos post I began thinking that "our" F1 engine could have an hybrid cooling system between oil, water and air. It would need little radiators, little pumps and ... this is getting too complicated, I dont like it, its not my engineering style.

Doing a little more brainstorming, about riff raff idea of the fuel itself helping in cooling and the kart engine fact that I posted (Fuel mixture is very very important in a air cooled engine) Im starting to think that the mixture with max cooling is not the one with best fuel consumption and power, something that goes against what we need in an F1 engine.

However, we still need some gross calculations here and begin to left the brainstorming aside and approach to reality.


As xpensive claims he is very good doing "from top of his mind" calculations, I left that to him

Merry Xmas!

[PlatinumZealot]

So there needs to be a fan on when the car is at low speeds. There is a problem with that though, the 90* V shape of the engine coupled with the large air box over the valley of the engine is going to make air flow difficult. Maybe a large angle v or flat 8 like the flat 12 in the porsche would be best. The crank center line would raise too.